Military Veterans suffering from posttraumatic stress disorder (PTSD) have been shown to exhibit increases in anger and aggressive behavior. Dysregulated anger and aggression can create fear and distress in spouses, family members, and friends resulting in deteriorated relationships, and can have a detrimental impact on Veterans' social, occupational and other important areas of functioning. Standard Cognitive Behavioral Therapy (CBT)-based interventions for anger and aggression are limited in part because they do not directly target the specific PTSD symptoms most strongly associated with aggression, namely increased hyperarousal and physiological reactivity. Further, they do not assist individuals in achieving awareness and insight into their anger states, which is necessary for effective management of anger and aggression. Mindfulness involves the self-regulation of attention on one's immediate experience and adopting an orientation of acceptance toward one's present experiences. Research studies conducted with civilians have found mindfulness to be effective in reducing anger and aggression. To date, no research has examined the effectiveness of mindfulness in decreasing anger and aggression among Veterans with PTSD. The proposed study aims to examine the initial efficacy of an established mindfulness intervention, Mindfulness Based Stress Reduction (MBSR) in decreasing trauma-related anger and aggression in Veterans with PTSD. The proposed project also aims to examine potential mechanisms of action accounting for its effects. Dr. Kachadourian is a postdoctoral fellow in the Clinical Neurosciences Division o the National Center for PTSD at the West Haven VA who has conducted basic research on alcohol, PTSD, anger, and aggression. Her current interests include conducting clinical trials to test novel therapeutic approaches like mindfulness meditation in treating anger and aggression among military Veterans with PTSD. TRAINING GOALS: The objectives for this CDA-2 application include advancing Dr. Kachadourian's expertise in conducting clinical trial research and advanced statistical analyses, and increasing her proficiency in mindfulness interventions. This will be accomplished through a rigorous program of formal didactics, collaboration with researchers experienced in clinical trials research and in mindfulness, PTSD, anger, and aggression, and a randomized controlled pilot study examining the initial efficacy of MBSR in decreasing anger and aggression among Veterans with PTSD. METHODS: Sixty Veterans with PTSD experiencing problems with anger and aggression will be randomly assigned to participate in a PTSD psychoeducational course (Trauma Recovery Education Class or TREC) or MBSR. All participants will attend a baseline, post-treatment, and 3-month follow-up session to assess changes in self-reported anger and aggression over time. At the post-treatment session, participants will also engage in a trauma-imagery procedure using trauma narratives developed at the baseline session. They then will participate in a laboratory paradigm designed to assess provoked aggression. In addition to examining whether participation in MBSR decreases self-reported levels of anger and aggression, this study will examine whether MBSR decreases aggression in participants after being exposed to trauma reminders in vivo. The extent to which mindfulness reduces physiological reactivity and increases emotion regulation will also be examined. The key question in this study is whether mindfulness decreases anger and aggression in Veterans with PTSD. Through this award, Dr. Kachadourian will be able to achieve her long-term goal of becoming an independent VA scientist with expertise in testing novel clinical interventions to treat problematic anger and aggression in military Veterans with PTSD.